A friend has "black" eyes. They're just really dark brown, but you can't really tell. I mean, I know you're just being "logical" desu, but yumyum obviously meant a girl with PRACTICALLY black eyes, because you rarely mean things technically when you're speaking casually like this. No need to be so pedantic, dude :,D

As for eye colour, it depends on the hair. Green-eyed redheads and blue-eyed brunettes are holsjglkfjgh.